OBJECTIVETo investigate the effects of aluminum on the integrity of blood brain barrier in juvenile rats.

METHODSThe 40-day old Sprague-Dawley (SD) rats were exposed to aluminium chloride by intraperitoneal injection, at a dose of Al3+ 0 mg/kg, 2.5 mg/kg, 5 mg/kg, 10 mg/kg, respectively. Morris water amaze system was used to test the learning and memory ability. The Evans blue content in brain was analyzed after injection. The ultrastructure's change of the blood brain barrier (BBB) was observed with transmission electron microscope. The expression of occluding protein in BBB was determined by Western blot method.

RESULTSAs compared with control group, the permeability of BBB in mid-level Al and high-level Al was enhanced (P <0.01), the expression of occluding protein was descended (P <0.01). The ultrastructures of the BBB were changed. No differences between every group on learning and memory ability (P>0.05).

CONCLUSIONSShort time and low dose of Al might not change the ability of learning and memory in juvenile rats, however the permeability and ultrastructures of the BBB might be significantly changed.